EP0283878A1 - Field effect transistor - Google Patents
Field effect transistor Download PDFInfo
- Publication number
- EP0283878A1 EP0283878A1 EP88103880A EP88103880A EP0283878A1 EP 0283878 A1 EP0283878 A1 EP 0283878A1 EP 88103880 A EP88103880 A EP 88103880A EP 88103880 A EP88103880 A EP 88103880A EP 0283878 A1 EP0283878 A1 EP 0283878A1
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- EP
- European Patent Office
- Prior art keywords
- layer
- gate
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- channel
- doped
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 230000005669 field effect Effects 0.000 title claims description 5
- 229910001218 Gallium arsenide Inorganic materials 0.000 claims abstract description 24
- 239000004065 semiconductor Substances 0.000 claims description 6
- 239000002800 charge carrier Substances 0.000 claims description 4
- 239000000463 material Substances 0.000 claims description 3
- JBRZTFJDHDCESZ-UHFFFAOYSA-N AsGa Chemical compound [As]#[Ga] JBRZTFJDHDCESZ-UHFFFAOYSA-N 0.000 abstract description 22
- FTWRSWRBSVXQPI-UHFFFAOYSA-N alumanylidynearsane;gallanylidynearsane Chemical compound [As]#[Al].[As]#[Ga] FTWRSWRBSVXQPI-UHFFFAOYSA-N 0.000 description 10
- 239000012212 insulator Substances 0.000 description 4
- 230000005684 electric field Effects 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 2
- 238000000151 deposition Methods 0.000 description 2
- 230000008021 deposition Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000007943 implant Substances 0.000 description 2
- 229910052710 silicon Inorganic materials 0.000 description 2
- 239000010703 silicon Substances 0.000 description 2
- GYHNNYVSQQEPJS-UHFFFAOYSA-N Gallium Chemical compound [Ga] GYHNNYVSQQEPJS-UHFFFAOYSA-N 0.000 description 1
- 229910000673 Indium arsenide Inorganic materials 0.000 description 1
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 1
- 229910000990 Ni alloy Inorganic materials 0.000 description 1
- MBGCACIOPCILDG-UHFFFAOYSA-N [Ni].[Ge].[Au] Chemical compound [Ni].[Ge].[Au] MBGCACIOPCILDG-UHFFFAOYSA-N 0.000 description 1
- 238000007792 addition Methods 0.000 description 1
- MDPILPRLPQYEEN-UHFFFAOYSA-N aluminium arsenide Chemical compound [As]#[Al] MDPILPRLPQYEEN-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000000969 carrier Substances 0.000 description 1
- 238000012217 deletion Methods 0.000 description 1
- 230000037430 deletion Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 229910052733 gallium Inorganic materials 0.000 description 1
- RPQDHPTXJYYUPQ-UHFFFAOYSA-N indium arsenide Chemical compound [In]#[As] RPQDHPTXJYYUPQ-UHFFFAOYSA-N 0.000 description 1
- 238000005468 ion implantation Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000001451 molecular beam epitaxy Methods 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 235000016768 molybdenum Nutrition 0.000 description 1
- 239000011733 molybdenum Substances 0.000 description 1
- 238000000206 photolithography Methods 0.000 description 1
- 238000001020 plasma etching Methods 0.000 description 1
- 239000003870 refractory metal Substances 0.000 description 1
- 229910021332 silicide Inorganic materials 0.000 description 1
- FVBUAEGBCNSCDD-UHFFFAOYSA-N silicide(4-) Chemical compound [Si-4] FVBUAEGBCNSCDD-UHFFFAOYSA-N 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 230000005641 tunneling Effects 0.000 description 1
- 230000005533 two-dimensional electron gas Effects 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L29/00—Semiconductor devices adapted for rectifying, amplifying, oscillating or switching, or capacitors or resistors with at least one potential-jump barrier or surface barrier, e.g. PN junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
- H01L29/40—Electrodes ; Multistep manufacturing processes therefor
- H01L29/43—Electrodes ; Multistep manufacturing processes therefor characterised by the materials of which they are formed
- H01L29/432—Heterojunction gate for field effect devices
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L29/00—Semiconductor devices adapted for rectifying, amplifying, oscillating or switching, or capacitors or resistors with at least one potential-jump barrier or surface barrier, e.g. PN junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
- H01L29/66—Types of semiconductor device ; Multistep manufacturing processes therefor
- H01L29/68—Types of semiconductor device ; Multistep manufacturing processes therefor controllable by only the electric current supplied, or only the electric potential applied, to an electrode which does not carry the current to be rectified, amplified or switched
- H01L29/76—Unipolar devices, e.g. field effect transistors
- H01L29/772—Field effect transistors
- H01L29/778—Field effect transistors with two-dimensional charge carrier gas channel, e.g. HEMT ; with two-dimensional charge-carrier layer formed at a heterojunction interface
- H01L29/7786—Field effect transistors with two-dimensional charge carrier gas channel, e.g. HEMT ; with two-dimensional charge-carrier layer formed at a heterojunction interface with direct single heterostructure, i.e. with wide bandgap layer formed on top of active layer, e.g. direct single heterostructure MIS-like HEMT
Definitions
- This invention relates in general to field effect transistor (FET) devices, and, in particular, to an improved saturable charge field effect transistor in which source and drain electrodes are separated by a channel region having an insulating portion on which the gate is deposited.
- FET field effect transistor
- a semiconductor-insulator-semiconductor field-effect transistor with a gallium arsenide gate is described in "A GaAs Gate Heterojunction FET", P.M. Solomon, et al., IEEE Electron Device Letters, Volume EPL-5, No. 9, September 1984. That transistor has a heavily doped n-type gallium arsenide gate with an undoped aluminum gallium arsenide gate insulator disposed on an undoped gallium arseinde layer. Sources and drains are fabricated from n-doped ion-implants. Compared to a silicon based MOSFET, the gallium arsenide gate FET has a lower threshold voltage, a higher speed of operation due to an extraordinary electron mobility at low temperatures, and a low power supply voltage requirement.
- the relatively low gate voltage has certain drawbacks.
- the low gate voltage results in an appreciable gate leakage current.
- the leakage-current is particularly significant in low power dissipation circuits such as complimentary and memory cells.
- an FET with a gallium arsenide gate is constructed with three layers of gallium arsenide.
- the bottem layer or layer closest to the aluminum gallium arsenide insulating layer is a layer of highly doped gallium arsenide.
- the next or intermediate layer is a layer of relatively lightly doped gallium arsenide.
- the upper or top most, ohmic contact layer is a layer of highly doped gallium arsenide.
- the doping is the same type i.e. it is all n-doped or all p-doped. In the preferred embodiment the doping is all n-doped with the intermediate layer less doped than either the bottom or the top layer.
- the alternate layers of gallium arsenide are applied to the gate by suitable means, such as molecular beam epitaxial deposition.
- the charge carrier type of doping of the layers is the same as the doping of the channel of the FET.
- the device operates on the principle that the charge density in the FET channel and the gate current depend upon the electric field in the insulating layer of aluminum gallium arsenide. By limiting the electric field at a given voltage, for instance, by choosing a thick enough insulator, both the gate current and the charge density in the channel will be limited.
- the invention achieves this end by interposing a depletion layer i.e. the lightly doped, intermediate gallium arsenide layer between the two heavily doped gallium arsenide layers in the gate.
- a depletion layer i.e. the lightly doped, intermediate gallium arsenide layer between the two heavily doped gallium arsenide layers in the gate.
- the intermediate layer under the influence of a large gate voltage, becomes depleted of charge carriers.
- the intermediate layer becomes an insulator that is in series with the aluminum gallium arsenide insulating layer. So, the effective insulating layer on the gate is dynamically increased as the result of increasing gate voltage.
- the bottom layer on the gate is only partially depleted and the FET is conductive and thus has a high transconductance.
- the bottom layer of the gate becomes completely depleted of charge carriers.
- the second layer or intermediate layer also becomes depleted and so the concentration of electrons in the channel underneath the gallium arsenide layer saturates at the value of sheet donor concentration of electrons in the bottom most gallium arsenide layer of the gate.
- a further increase in gate voltage will cause only a small or negligable increase in drain or gate current.
- the thickness of the gate insulator is now that of the depleted intermediate region in series with the aluminum gallium arsenide layer.
- FIG. 1 there is generally shown a saturable charge FET 10.
- the structure of the FET 10 has a (100)-oriented semi-insulating gallium arsenide substrate 6.
- layer 6 On top of layer 6 is a layer 5 of undoped gallium arsenide.
- Layer 5 is approximately one micron thick and is grown by molecular beam epitaxial methods.
- layer 4 On top of layer 5 is layer 4 comprising a layer of undoped Al x Ga 1-x As also grown by molecular beam epitaxy.
- Layer 4 may be from 10nm to 100 nm thick and the preferred thickness is approximately 20nm.
- the range of x in the Al x Ga 1-x As layer 4 is between 0.3 and 0.8, preferably 0.5.
- Source and drain regions 18, 19 may be formed by ion implantation or diffusing of n-type doping. It is preferred to implant silicon at 60 KeV and 5 ⁇ 1013cm ⁇ 3.
- Ohmic contracts 16, 17 are fabricated in a customary manner using a gold-germanium nickel alloy or other suitable contact components. Ohmic contacts 16 and 17, together with regions 18 and 19 form source and drain electrodes 11 and 13, respectively.
- the gate 12 of the FET 10 includes a bottom layer 1 adjacent the insulating layer 4.
- Layer 1 comprises a layer of gallium arsenide that is about 100 Angstroms thick and n-doped to approximately 1018cm ⁇ 3.
- the doping times the thickness of layer 1 is equal to the maximum charge density desired in the FET channel.
- the doping in layer 1 is large enough to not appreciably degrade the transconductance of the FET.
- the preferred range of doping is 5 ⁇ 1011cm ⁇ 2 to 2 ⁇ 1012cm ⁇ 2 for layer 1.
- Layer 2 is also composed of GaAs and is doped to a much lesser degree than is layer 1; about 1016cm ⁇ 3 is typical. Layer 2 is limited in thickness by the planarity constraints on the FET 10.
- layer 2 can be as thick as practically possible and 0.2nm is typical.
- Layer 3 is also composed of GaAs which is doped as heavily as possible and is thick enough to ensure a good contact with ohmic contact 7. Doping in the order 6 ⁇ 1018cm ⁇ 3 is typical and a thickness of 500 Angstroms would be desirable.
- An additional layer (not shown) of indium arsenide may be deposited on layer 3 to assist in the further fabrication of ohmic contract with layer 3.
- a 150nm layer of a refractory metal such as molybdenum or tungstem silicide is deposited to form the contact layer 7. That layer is patterned using reactive ion etching and plasma to expose the upper surface of the aluminum gallium arsenide layer 4. After formation of the source and drain regions noted above, the device 10 is annealed and ohmic contacts 16, 17 are formed. The device 10 has a gate length of approximately 1 micron or as small as photolithography permits.
- the threshold voltage of the device 10 is near zero.
- a heterojunction forms in the device between the aluminum gallium arsenide layer 4 and the gallium arsenide layer 5.
- carriers appearing at the source are rapidly transmitted via the two dimensional gas to the drain.
- This typical operation of the device 10 is diagramically presented in Figure 2.
- the layer 1 is only partially depleted and layer 2 has no influence on the characteristics of device 10 since it is essentially a conducting layer.
- the effective thickness of the insulating layers of gate 12 is now that of the depleted region 2 in series with aluminum gallium arsenide layer 4.
- the sum of these two regions may be between 300 to 2,000 Angstroms thick. Such thickness will be sufficient for adaquately reducing gate leakage current at larger gate voltages.
- the FET 10 is an n-channel device.
- doping concentrations as well as different thickness layers and other materials may also be used, e.g., p-channel devices could be fabricated with suitable doping.
- the layers 1, 2, 3 are deposited on the gate by will known methods of molecular epitaxial deposition but other methods are usable. So, various modifications, substitutions, additions and deletions may be made without departing from the spirit and scope of the invention as is defined by the appended claims.
Abstract
Description
- This invention relates in general to field effect transistor (FET) devices, and, in particular, to an improved saturable charge field effect transistor in which source and drain electrodes are separated by a channel region having an insulating portion on which the gate is deposited.
- A semiconductor-insulator-semiconductor field-effect transistor with a gallium arsenide gate is described in "A GaAs Gate Heterojunction FET", P.M. Solomon, et al., IEEE Electron Device Letters, Volume EPL-5, No. 9, September 1984. That transistor has a heavily doped n-type gallium arsenide gate with an undoped aluminum gallium arsenide gate insulator disposed on an undoped gallium arseinde layer. Sources and drains are fabricated from n-doped ion-implants. Compared to a silicon based MOSFET, the gallium arsenide gate FET has a lower threshold voltage, a higher speed of operation due to an extraordinary electron mobility at low temperatures, and a low power supply voltage requirement.
- However, the relatively low gate voltage has certain drawbacks. In particular, the low gate voltage results in an appreciable gate leakage current. The leakage-current is particularly significant in low power dissipation circuits such as complimentary and memory cells. In such cells, it is desirable to have very thin insulating layers of aluminum gallium arsenide in order to yield a higher transconductance. It is also desirable to operate devices with larger gate voltages. In both cases, the thinner layer of aluminum gallium arsenide and the increased operating voltage on the gate increases the undesired leakage current.
- So, it is desirable to have an FET as described above with a gate structure that operates at higher voltages and has less leakage current. It is particularly desirable to have such a device without any compromise in the speed or performance of the GaAs gate FET.
- The foregoing desired objects are achieved by the FET having a multi-layer gate structure as claimed. In particular, an FET with a gallium arsenide gate is constructed with three layers of gallium arsenide. The bottem layer or layer closest to the aluminum gallium arsenide insulating layer is a layer of highly doped gallium arsenide. The next or intermediate layer is a layer of relatively lightly doped gallium arsenide. The upper or top most, ohmic contact layer is a layer of highly doped gallium arsenide. In all layers the doping is the same type i.e. it is all n-doped or all p-doped. In the preferred embodiment the doping is all n-doped with the intermediate layer less doped than either the bottom or the top layer.
- The alternate layers of gallium arsenide are applied to the gate by suitable means, such as molecular beam epitaxial deposition. The charge carrier type of doping of the layers is the same as the doping of the channel of the FET. The device operates on the principle that the charge density in the FET channel and the gate current depend upon the electric field in the insulating layer of aluminum gallium arsenide. By limiting the electric field at a given voltage, for instance, by choosing a thick enough insulator, both the gate current and the charge density in the channel will be limited.
- The invention achieves this end by interposing a depletion layer i.e. the lightly doped, intermediate gallium arsenide layer between the two heavily doped gallium arsenide layers in the gate. As such, the intermediate layer, under the influence of a large gate voltage, becomes depleted of charge carriers. When depletion occurs, the intermediate layer becomes an insulator that is in series with the aluminum gallium arsenide insulating layer. So, the effective insulating layer on the gate is dynamically increased as the result of increasing gate voltage.
- For low gate voltages, the bottom layer on the gate is only partially depleted and the FET is conductive and thus has a high transconductance. However, for large gate voltages, the bottom layer of the gate becomes completely depleted of charge carriers. The second layer or intermediate layer also becomes depleted and so the concentration of electrons in the channel underneath the gallium arsenide layer saturates at the value of sheet donor concentration of electrons in the bottom most gallium arsenide layer of the gate. A further increase in gate voltage will cause only a small or negligable increase in drain or gate current. In effect, the thickness of the gate insulator is now that of the depleted intermediate region in series with the aluminum gallium arsenide layer.
- The foregoing summary of the invention can be better understood by reference to the following detailed description when read in conjunction with the accompanying drawing wherein:
- Figure 1 is a cross-sectional schematic view of the invention:
- Figure 2 is an energy band diagram of the cross-section of the invention for low gate voltages slightly greater than zero;
- Figure 3 is an energy band diagram of the invention for relatively large gate voltages.
- In Figure 1 there is generally shown a
saturable charge FET 10. The structure of the FET 10 has a (100)-oriented semi-insulating gallium arsenide substrate 6. On top of layer 6 is alayer 5 of undoped gallium arsenide.Layer 5 is approximately one micron thick and is grown by molecular beam epitaxial methods. On top oflayer 5 is layer 4 comprising a layer of undoped AlxGa1-xAs also grown by molecular beam epitaxy. Layer 4 may be from 10nm to 100 nm thick and the preferred thickness is approximately 20nm. The range of x in the AlxGa1-xAs layer 4 is between 0.3 and 0.8, preferably 0.5. Source anddrain regions Ohmic contracts Ohmic contacts regions drain electrodes - The
gate 12 of the FET 10 includes abottom layer 1 adjacent the insulating layer 4.Layer 1 comprises a layer of gallium arsenide that is about 100 Angstroms thick and n-doped to approximately 10¹⁸cm⁻³. The doping times the thickness oflayer 1 is equal to the maximum charge density desired in the FET channel. The doping inlayer 1 is large enough to not appreciably degrade the transconductance of the FET. The preferred range of doping is 5×10¹¹cm⁻² to 2×10¹²cm⁻² forlayer 1.Layer 2 is also composed of GaAs and is doped to a much lesser degree than islayer 1; about 10¹⁶cm⁻³ is typical.Layer 2 is limited in thickness by the planarity constraints on the FET 10. Otherwise,layer 2 can be as thick as practically possible and 0.2nm is typical.Layer 3 is also composed of GaAs which is doped as heavily as possible and is thick enough to ensure a good contact with ohmic contact 7. Doping in the order 6 × 10¹⁸cm⁻³ is typical and a thickness of 500 Angstroms would be desirable. An additional layer (not shown) of indium arsenide may be deposited onlayer 3 to assist in the further fabrication of ohmic contract withlayer 3. - A 150nm layer of a refractory metal such as molybdenum or tungstem silicide is deposited to form the contact layer 7. That layer is patterned using reactive ion etching and plasma to expose the upper surface of the aluminum gallium arsenide layer 4. After formation of the source and drain regions noted above, the
device 10 is annealed andohmic contacts device 10 has a gate length of approximately 1 micron or as small as photolithography permits. - In operation, the threshold voltage of the
device 10 is near zero. A heterojunction forms in the device between the aluminum gallium arsenide layer 4 and thegallium arsenide layer 5. There is a two dimensional electron gas at that interface. As such, carriers appearing at the source are rapidly transmitted via the two dimensional gas to the drain. This typical operation of thedevice 10 is diagramically presented in Figure 2. For low gate voltages, thelayer 1 is only partially depleted andlayer 2 has no influence on the characteristics ofdevice 10 since it is essentially a conducting layer. - When the gate voltage is increased, the affects of the increased voltage upon the gate layers 1, 2, 3 produces a pronounced change in the operation of the
device 10. In this regard, reference is made to Figure 3. There it is shown that for a large gate voltage,layer 1 will become depleted. For a sufficiently lightly dopedlayer 2, it too will become depleted. As such, the electron concentration in the channel underneath thegate 12 and between thesource region 18 and thedrain region 19 saturates at the value of sheet donor concentration inlayer 1. By Gauss' law, the electric field in aluminum arsenide layer 4 is fixed at a value determined by the donor sheet concentration inlayer 1, and the gate tunneling current is fixed. A further increase in gate voltage will cause only a small increase in drain and gate current. This is so because the effective thickness of the insulating layers ofgate 12 is now that of the depletedregion 2 in series with aluminum gallium arsenide layer 4. The sum of these two regions may be between 300 to 2,000 Angstroms thick. Such thickness will be sufficient for adaquately reducing gate leakage current at larger gate voltages. - In the foregoing description, the
FET 10, is an n-channel device. However, those skilled in the art will appreciate that different types of doping concentrations as well as different thickness layers and other materials may also be used, e.g., p-channel devices could be fabricated with suitable doping. Also, thelayers
Claims (10)
a semiconductor gate (12) in proximity to the insulating portion (4) of said channel, said gate having a first high conductivity semiconductor layer (1) immediately adjacent said insulating portion (4) of said channel, and a second depletable low conductivity semiconductor layer (2) separating said first layer (1) from a third (3) high conductivity semiconductor external contact layer.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US28640 | 1979-04-09 | ||
US07/028,640 US4965645A (en) | 1987-03-20 | 1987-03-20 | Saturable charge FET |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0283878A1 true EP0283878A1 (en) | 1988-09-28 |
EP0283878B1 EP0283878B1 (en) | 1995-07-05 |
Family
ID=21844609
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP88103880A Expired - Lifetime EP0283878B1 (en) | 1987-03-20 | 1988-03-11 | Field effect transistor |
Country Status (4)
Country | Link |
---|---|
US (1) | US4965645A (en) |
EP (1) | EP0283878B1 (en) |
JP (1) | JPH0797638B2 (en) |
DE (1) | DE3854098T2 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5060031A (en) * | 1990-09-18 | 1991-10-22 | Motorola, Inc | Complementary heterojunction field effect transistor with an anisotype N+ ga-channel devices |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5125601A (en) * | 1991-12-26 | 1992-06-30 | The United States Of America As Represented By The Administrator, National Aeronautics And Space Administration | Payload retention device |
US5514891A (en) * | 1995-06-02 | 1996-05-07 | Motorola | N-type HIGFET and method |
US6331486B1 (en) * | 2000-03-06 | 2001-12-18 | International Business Machines Corporation | Method and structure for reduction of contact resistance of metal silicides using a metal-germanium alloy |
CN110828564B (en) * | 2018-08-13 | 2022-04-08 | 香港科技大学 | Field effect transistor with semiconducting gate |
Family Cites Families (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3279795D1 (en) * | 1981-04-23 | 1989-08-03 | Fujitsu Ltd | High electron mobility semiconductor device |
US4442445A (en) * | 1981-11-23 | 1984-04-10 | The United States Of America As Represented By The Secretary Of The Army | Planar doped barrier gate field effect transistor |
JPS5932173A (en) * | 1982-08-16 | 1984-02-21 | Toshiba Corp | Manufacture of field effect transistor |
US4583105A (en) * | 1982-12-30 | 1986-04-15 | International Business Machines Corporation | Double heterojunction FET with ohmic semiconductor gate and controllable low threshold voltage |
US4590502A (en) * | 1983-03-07 | 1986-05-20 | University Of Illinois | Camel gate field effect transistor device |
JPS59207667A (en) * | 1983-05-11 | 1984-11-24 | Hitachi Ltd | Semiconductor device |
JPS59210673A (en) * | 1983-05-16 | 1984-11-29 | Fujitsu Ltd | Semiconductor device |
JPS6028273A (en) * | 1983-07-26 | 1985-02-13 | Nec Corp | Semiconductor device |
JPS60117680A (en) * | 1983-11-29 | 1985-06-25 | Nippon Telegr & Teleph Corp <Ntt> | High-speed field effect transistor |
JPH0810751B2 (en) * | 1983-12-23 | 1996-01-31 | 株式会社日立製作所 | Semiconductor device |
JPS60140874A (en) * | 1983-12-28 | 1985-07-25 | Hitachi Ltd | Semiconductor device |
JPS60189268A (en) * | 1984-03-08 | 1985-09-26 | Fujitsu Ltd | Semiconductor device |
JPH0230182B2 (en) * | 1984-03-15 | 1990-07-04 | Nippon Electric Co | HANDOTAISOCHI |
JPH0695531B2 (en) * | 1985-04-08 | 1994-11-24 | 日本電信電話株式会社 | Field effect transistor |
-
1987
- 1987-03-20 US US07/028,640 patent/US4965645A/en not_active Expired - Lifetime
-
1988
- 1988-01-14 JP JP63005032A patent/JPH0797638B2/en not_active Expired - Lifetime
- 1988-03-11 DE DE3854098T patent/DE3854098T2/en not_active Expired - Fee Related
- 1988-03-11 EP EP88103880A patent/EP0283878B1/en not_active Expired - Lifetime
Non-Patent Citations (2)
Title |
---|
ELECTRONIC LETTERS, vol. 20, no. 21, 11th October 1984, pages 854-855, Staines, Middlesex, GB; N.C. CIRILLO et al.: "Novel multilayer modulation doped (Al,Ga)As/GaAs structures for self-aligned gate FETs" * |
PATENT ABSTRACTS OF JAPAN, vol. 10, no. 379 (E-465)[2436], 18th December 1986; & JP-A-61 171 170 (HITACHI LTD.) 01-08-1986 * |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5060031A (en) * | 1990-09-18 | 1991-10-22 | Motorola, Inc | Complementary heterojunction field effect transistor with an anisotype N+ ga-channel devices |
Also Published As
Publication number | Publication date |
---|---|
JPH0797638B2 (en) | 1995-10-18 |
US4965645A (en) | 1990-10-23 |
JPS63244779A (en) | 1988-10-12 |
DE3854098T2 (en) | 1996-02-29 |
DE3854098D1 (en) | 1995-08-10 |
EP0283878B1 (en) | 1995-07-05 |
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